1. Field of the Invention
The present invention relates to a vehicle brake apparatus including a master cylinder having a master piston of which back side faces a boosted hydraulic pressure chamber and a casing accommodating the master piston in a slidable manner, a hydraulic pressure generating source, a reservoir, and a pressure regulating valve unit adapted to regulate an output hydraulic pressure of the hydraulic pressure generating source in response to an input of brake application effort from a brake operation member for application to the boosted hydraulic pressure chamber, the master cylinder being connected to wheel brakes.
2. Description of Related Art
A vehicle brake apparatus like one described above is known in, for example, Japanese Patent Unexamined Publication No. JP-A-2002-264795 and the like.
In the conventional brake apparatus described above, however, the pressure regulating valve unit is configured to mechanically operate in response to an input of brake application effort, and since this configuration not only makes the construction of the pressure regulating valve unit complex but also permits only a pressure regulation at a predetermined pressure in response to the input of brake application effort, when attempting to apply this very brake system to other model lines each having a different specification, a newly specified pressure regulating valve unit has to be prepared in consideration of boost ratio, stroke and the like which are specific to a model line to which the brake system is attempted to be applied, this increasing the number of kinds of components parts involved.
Further in the vehicle brake apparatus disclosed in JP-A-2002-264795 above, a hydraulic pressure generating source is such as to include a pump and a high pressure accumulator which is connected to the pump, and since it has to stand for high pressure, the high pressure accumulator has a housing whose thickness is thick and hence the weight thereof is increased much, whereby the hydraulic pressure generating source becomes heavy, and the layout performance thereof is deteriorated. Then, although it has been considered that the hydraulic pressure generating source is configured by only the pump by deleting the high pressure accumulator, when depending upon an approach in which only an increase in pump head is sought for, the pressure raising response at the initial stage of the brake applying operation is reduced.